Sound-receiving apparatus



1929- R. L. WILLIAMS 1,725,038

SOUND RECEIVING APPARATUS Filed Nov. 15, 1924 ATTORNEY:

' diaphra ROBERT LONGIELLOW WILLIAMS, OF NEWTON, MASSACHUSETTS, ASSIGNOR TO SUB- MABINE SIGNAL CORPORATION, OF BOSTON, MASSACHTRSETTS, A CORPORATION OF DELAWARE.

SOUND-RECEIVING APPARATUS.

Application filed November 15, 1924. Serial No. 250,218.

The present invention relates to the reception of sound waves and more particularly to the reception of compressional waves in water or other similar medium in which the sound or compressional waves act to operate an electric circuit either to open or to close the same.

In an embodiment described in this specification the circuit is broken by the action of the incoming signal upon a diaphragm which, in its motion, opens an electrical contact be- .tween two conductive metals, preferably platinum sealed in a gas chamber filled with nitrogen to prevent oxidation of the contacts. The object of the invention described in the present specification is to obtain an apparatus which will indicate by the opening of an electrical contact an incoming signal.

Another purpose of the present invention is to have the incoming sound or compressional signal operate to break a current of considerable value either directly or indirectlv by the action ofthe signal itself and thus mav be useful for operating any kind of electrical mechanism without requiring amplification as is generally necessary when a microphone is used as a receiver.

It is also the purpose of this construction to have such a device operate by the signal alone and not by stray sounds which come in contact with the device.

In the embodiment described below the hydrophonic relay as it may be called has a mounted on a watertight case, the diap ragm supporting an insulated electrical contact. A second electrical contact normally resting upon the first is mounted upon a pivoted balanced rod insulated as the first contact. When the incoming signal agitates the diaphragm the second contact is thrown off by the first and the circuit is broken. Further objects of the present invention and details of construction will be learned from the description and drawing of the specification, in which Fi ure 1 represents a cross sectional view of t e apparatus.

Figure 2 an enlarged view. of the details of the contact mechanism and circuit. taken partly along line 2-2 of Figure 3. Figure 3 shows a plan view of Figure 2 and Figure 4 a detail of the pivot.

In Figgire 1 the device shown isadapted to pass t rough the cylindrical portion of a valve and have the diaphragm 1 exposed to the water or transmitting medium. The dia- In the center of the dia hragm is a boss 21 which is either a part of t e metal of the diaphragm or a piece of metal spot welded to the diaphragm. A bakelite or other insulating bushing 22 is secured in this boss and a platinum .point 23 is set in the bushing.

' Above the platinum point is a platinum stud 24 which sets firmly ina stud 25 threaded at the other end and adjustable-in the ivoted arm 18. A spindle 19 which passes t rough the arm 18'is pivoted in a jewel bearing 32 at both ends as indicated in Figure 3 and insulates the arm 18 from the lower platinum contact 23.

A conductor 35 is soldered or otherwise attached to the spindle 19 in the manner shown. in Figure 2 to allow free motion of the spindle. A'second conductor 20 of thin wire is connected to the platinum point 23. These two wires are led to the indicating circuit which, in the present case, consists of the battery 28, the primary 29 of a transformer, and a secondary 30 in which the potential induced by breaking of the platinum contacts 23 and 24 operates an indicating mechanism, in the present illustration, an electric luminous discharge in a gaseous tube 31.

The spindle 19 is supported between the prongs of the U shaped member 14 which rests upon an arm 13 integral with the shell 5 as shown in Figures 1 and 2. Machine screws 15 in the cross piece 17 of the support pass through an insulating bushing 16, thus insulating the pivoted arm 18 in event the jewel bearing is not sufiicient insulation.

The arm 18 has an adjustable weight 11 which may be positioned upon the arm in the place desired to obtain the roper balance so that the contact 23 and 24 Wlll open under the action of the incoming signal. The stud 25 V vents the bar 18 from moving excessively out of the normal position and thereby prevents any strain upon the connection to the spindle 19 or the jewel bearing.

About the shell 5 is a soft rubber casing l which has a serving 34 to bind the rubber tightly in place. a sound insulator and also to make a good fit in the cylindrical valve in which the device is inserted. A stem 8 has a fiangti at its lower end, through which machine screws 7 pass holding the shell 5 securely to the stem... A watertight and airtight gasket 39 of a suitable character is inserted between the pieces 6 and 5 to insure that the inner space is tightly sealed. The conducting leads pass throu h the stem which is sealed at the upper end by a suitable bushing as shown in Figure '1. There is provided a hole 9 in the stem 8 which can be used'for testin the device for leaks and which is sealed wit a test plug when the testing is completed.

Since the leads 12 have some play in the stem 8 the hole 9 may be used to pump nitrogen into the space after the air has been pumped out.

As has been explained above, the present This rubber serves to act as device may be adapted to be inserted in the skin of a vessel through a cylinder of agate valve. With this end in view the outer end of the receiver is constructed in apiston head fashion while the stem resembles a piston rod. However, this receiver may also be susended in a water tank within a vessel or even ung overboard as the conditions may demand.

The device which has been described above usuallyoperates in a position approximately that as shown in Figure 1. Due to the fact that the only means which hold the two platinum contacts together is the action of gravity on a balanced arm, this pivoted arm must normally be in an approximately horizontal position. It is conceivable that this condition need not be specifically com lied with as long as the action of gravity just olds the contacts together. The arm could possibly be of other shapes and still perform the above function properly. r

The operation will be described briefly. The incoming signal acting upon the diaphragm causes the latter to vibrate. In the present case this vibration is somewhat damped so that it does not persist as long as a perfectly free vibration of a free diaphragm. he lower platinum contact will, however, vibrats somewhat. On the first vibration the 218111111111 point 23 will move upwards, there throwing 0d and opening the contact with t e upper platinum stud 24, since the latter acts as 2. ve .li ht mass the to the careful ad= mes es will not be thrown off again unless the signal is continued.

There is a distinct advantage in the present type of receiver, especially where the signal is short as is usually the case, in the measurement of distance by submarine signals and radio signals, or in the measurement of depth where a signal is emitted and the returning echo operates an indicator. Another advantage in the present device is that considerable current can be broken and, therefore, the signal is at the same time amplified;

Having now described my invention 1 claim:

1. In a system for receiving and indicating submarine sound signals, a submarine sound receiver comprising a water-tight casing, a diaphragm forming one side of said casing and adapted to be exposed in a substantially horizontal position to the water, an electrode mounted within said casing substantially on the center of said diaphragm, an arm carrying near one end a second electrode adapted to make a light contact with said first electrode, and means for freely pivoting and balancing said arm substantially in a plane parallel to said diaphragm including a counter balanceadjustable on said arm.

2. In a system for receiving and indicating submarine sound signals, a submarine sound receiver comprising a watertight casing, a diaphragm forming one side of said casing, a soft rubber sheet covering substantially the entire inner surface of said diaphragm, said diaphragm being exposed in a substantially horizontal position to the water, an electrode mounted within said casing substantially on the center of said diaphragm, an arm carry ing near one end a second electrode adapted to make alight contact with said first elec trode, and means for pivoting freely and balancing said arm substantially in a plane and adapted to be exposed in a substantially horizontal position to the water, an electrode mounted within said casing substantially on the center of said diaphragm, an arm carrying near one end a second electrode adapted to make alight contactwith said first-electrode, means for freely pivoting and balancing said arm substantially in a plane parallel to said diaphragm including a counter. balance adjustable on said arm, and means for limiting the swing of said arm.

d. A system forvrec'eiving and indicating submarine sound signals including an electrically energized circuit and a submarine sound receiver having a pair of contacts normally completing said electrical circuit,

said subarme sound. receivercomprisingi a watertight case, a diaphragm closing a part of said case, one of said contacts mounted directly on said diaphragm, means for pivoting the other of said contacts with freedom of movement to and from said first contact including an arm on which said contact is mounted and a counter balance adjustable to such a position on said arm that the contacts make light contact with each other, an inert gas filling the space within said casing, and means comprising in part said electrical circuit and including a step up transformer and a gaseous discharge indicator for rapidly flashing said indicator upon the receipt of a sound,

5. A system for receiving and indicating submarine sound signals comprising a submarine sound receiver consisting of a watertight casing, a diaphragm forming a part of said casing having a soft rubber s eetcovering the inner surface thereof, a pair of contacts, means for mounting one of said contacts on said diaphragm, means for pivoting and balancing the other of said contacts freely on said first contact including an arm on which said contact is mounted and a counter balance adjustable to such a osition on said arm that the contacts make ight contact with each other whereby the receipt of a sound impulse will immediately open said contacts and an indicating circuit operated by the opening of said contacts for producing a momentary discharge across a gaseous tube comprising said gaseous tube,

a transformer operating the same,-and an electrical circuit having a source of energy connecting said transformer and said contacts.

6. In a submarine sound receiver a diaphragm for receivin the sound waves, an electrode. mounted su stantially on the center of said diaphragm, an arm, adjustable means for mounting a second electrode in electrode mounted su stantially on the center of said diaphragm, an arm, adjustable means for mounting a second electrode in said arm including a threaded stud on which said electrode is mounted, threading into said arm, means for pivoting said arm to allow freedom of movement of said second electrode to and away from said first electrode and adjustable means for balancing said arm in a substantially horizontal position comprising a screw threaded portion provided on said arm and'a counter weight threadin said screw threaded portion whereby the esired ressure between said electrodes may be 0 tained.

8. In a submarine sound receiver a diaphragm for receivin the sound waves, an electrode mounted su stantially on the center of said diaphragm, a second electrode positioned normally in contact with said first electrode and directly bearing on the latter, an arm positioned substantially parallel to said diaphra means for mounting said second electro e in said arm, a forked support carried b the casing, means for pivoting said arm lietween the forks of said support to allow a free up and down movement of said arm, and means for adjusting the pressure exerted by the second electrode on the first.

In testimony whereof I afiix my signature.

ROBERT LONGFELLOW WILLIAMS. 

